|
Posted by baalke on September 20, 2007, 11:56 am
Please log in for more thread options
http://www.esa.int/SPECIALS/Mars_Express/SEMWZZMPQ5F_0.html
The mysterious ridges at the mouth of Tiu Valles
European Space Agency
Mars Express
12 September 2007
These images taken by the High Resolution Stereo Camera (HRSC) on
board
Mars Express show the mouth of the Tiu Valles channel system on the
red
planet.
The pictures were taken in orbit 3103 on 10 June 2006 with a ground
resolution of approximately 16 metres per pixel.
The mouth of Tiu Valles is an estuary-like landform. On Earth, an
estuary is the tidal mouth of a river valley, or the end that meets
the
sea and fresh water comes into contact with seawater. In such an area,
tidal effects are evident.
[Map showing Tiu Valles in context]
Tiu Valles is located at approximately 27=C2=B0 North and 330=C2=B0 East. T=
he
sun
illuminates the scene from the North West, the lower left-hand side in
the image.
Tiu Valles originates in the equatorial chaotic terrains at the mouth,
at the eastern end of Valles Marineris. The morphology of this chaotic
terrain is dominated by large-scale remnant massifs, which are large
relief masses that have been moved and weathered as a block. These are
randomly oriented and heavily eroded.
>From there, the region extends to the north over a distance of 1500 km
before terminating in Chryse Planitia. Along with Kasei Valles and
Ares
Valles, Tiu Valles is one of the major outflow channels entering the
Chryse Planitia plain.
[Tiu Valles perspective view]
The scene in the images covers an area of approximately 140 by 80 km
at
the mouth of Tiu Valles. The region was made famous in 1997 when rover
Sojourner of NASA=E2s Pathfinder mission landed about 600 km south-west
of
the mapped area.
Visible in the lower part of the image are remnants of a once
'streamlined' island. The upper part of the scene covers the mouth of
Tiu Valles nearly in its entire width, approximately 55 km.
Its winding, meandering ridges, bound by depressions, are eye-
catching.
The exact processes that formed these odd structures are unknown. One
possibility is that during floods, water or water-rich surface layers
came in contact with lava from the surrounding areas, which then might
have led to the formation of these mysterious ridges.
[Tiu Valles perspective view]
The colour scenes have been derived from the three HRSC-colour
channels
and the nadir channel. The perspective views have been calculated from
the digital terrain model derived from the HRSC stereo channels. The
anaglyph image was calculated from the nadir channel and one stereo
channel, stereoscopic glasses are required to for viewing. The black
and
white high-resolution images were derived from the nadir channel which
provides the highest level of detail.
[Tiu Valles nadir view]
[Tiu Valles 3D image]
| 
XML Sitemap